Probably better to post in the github issue rather than replying here.
Oh, yeah, at that point it’ll be a scalability clusterfuck. No idea what the solution is. Maybe something with persistent caches run by third parties or something? That actually would be fine, since all the actions are signed with the private key of the actor, I think.
ActivityPub is not to me a real great designed protocol but it’s whatever. Usually the key part for social networks is the “social” part of it; the protocol or the web site can be pure shite and if people like interacting with the other people there then it’s fine. But yes, you are correct that beyond a certain point of scalability there are some dragons lurking that don’t have obvious weak spots.
The problem is not with ActivityPub, but the implementations. No one ever claimed that it should be only a push-based system, but it seems that everyone working on AP software can only think in terms of server-to-server interactions to get the data and then reinvent the wheel by developing their ad-hoc API.
AP is fine if we treat it as a messaging protocol and use it to power offline-first applications. The devices do not need to have all the network’s data, just the one that the user has actively interacted with.
